1. Field of the Invention
This invention pertains to automatically lubricating the upper cylinder area of an internal combustion engine.
2. Description of the Prior Art
Internal combustion engines generally are inadequately lubricated in their upper cylinder areas. As a result, it is well-known that the cylinders and other parts of an internal combustion engine have a much shorter life span than the parts of a diesel engine. In addition, the parts operate less efficiently than they would if properly lubricated. With the advent of non-leaded gasolines, and especially high octane non-leaded gasolines, that are dryer burning than leaded gasolines, this problem of inadequate lubrication is exacerbated. Internal combustion engines that operate with methane fuel are even more notoriously poorly lubricated in their upper cylinder areas than are gasoline internal combustion engines because of the extremely dry burning conditions. The problem exists with internal combustion engines with fuel injectors as well as those without.
Attempts in the prior art to provide upper cylinder area lubrication include the system described in U.S. Pat. No. 3,115,874, which basically puts lubricant into the upper cylinder by drawing a vacuum on a lubricant reservoir and applying the lubricant through a valve in a manifold. Metering is provided through a "bi-metal" valve that determines the opening depending on the heat of the engine. The amount of lubricant applied is often entirely too much, however, since lubricant is constantly applied. As a result, the lubricant reservoir empties faster than is economical or practical and there is a gumming effect on the operating parts that are over-lubricated.
U.S Pat. No. 2,721,545 describes another system for lubricating the upper cylinder area of an internal combustion engine, this system using a fine spray or mist head to dispense the lubricant more uniformly over the parts than with a delivery scheme not including such a head. The lubricant is constantly applied, however, as with the '874 system. There is no known spray head that dispenses with a fine enough spray to be both efficient and non-wasteful. That is, the '545 scheme also dispenses much too much lubricant to be commercially acceptable.
Therefore, it is a feature of the present invention to provide an improved system for lubricating the upper cylinder area of an internal combustion engine that dispenses only the required amount of lubricant at intermittent intervals.
It is another feature of the present invention to provide an improved system for lubricating the upper cylinder area of an internal combustion engine that utilizes long-acting solid state timer means.
It is still another feature of the present invention to provide an improved system for lubricating the upper cylinder area of an internal combustion engine that utilizes a long-acting electric pump that does not impart a constant pressure condition on the operating engine parts, as with the '874 system.